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Mechanisms of cell reprogramming by pluripotency-related transcription factors or nuclear transfer seem to be mediated by similar pathways, and the study of the contribution of OCT4 and SOX2 in both processes may help elucidate the mechanisms responsible for pluripotency. Bovine fibroblasts expressing exogenous OCT4 or SOX2, or both, were analyzed regarding the expression of pluripotency factors and imprinted genes H19 and IGF2R, and used for in vitro reprogramming. The expression of the H19 gene was increased in the control sorted group, and putative iPSC-like cells were obtained when cells were not submitted to cell sorting. When sorted cells expressing OCT4, SOX2, or none (control) were used as donor cells for somatic cell nuclear transfer, fusion rates were 60.0% vs. 64.95% and 70.53% vs. 67.24% for SOX2 vs. control and OCT4 vs. control groups, respectively; cleavage rates were 66.66% vs. 81.68% and 86.47% vs. 85.18%, respectively; blastocyst rates were 33.05% vs. 44.15% and 52.06% vs. 44.78%, respectively. These results show that the production of embryos by NT resulted in similar rates of in vitro developmental competence compared to control cells regardless of different profiles of pluripotency-related gene expression presented by donor cells; however, induced reprogramming was compromised after cell sorting.
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Hepatic microenvironment plays an essential role in liver regeneration, providing the necessary conditions for cell proliferation, differentiation and tissue rearrangement. One of the key factors for hepatic tissue reconstruction is the extracellular matrix (ECM), which through collagenous and non-collagenous proteins provide a three-dimensional structure that confers support for cell adhesion and assists on their survival and maintenance. In this scenario, placental ECM may be eligible for hepatic tissue reconstruction, once these scaffolds hold the major components required for cell support. Therefore, this preliminary study aimed to access the possibility of mouse embryonic stem cells differentiation into hepatocyte-like cells on placental scaffolds in a three-dimensional dynamic system using a Rotary Cell Culture System. Following a four-phase differentiation protocol that simulates liver embryonic development events, the preliminary results showed that a significant quantity of cells adhered and interacted with the scaffold through outer and inner surfaces. Positive immunolabelling for alpha fetus protein and CK7 suggest presence of hepatoblast phenotype cells, and CK18 and Albumin positive immunolabelling suggest the presence of hepatocyte-like phenotype cells, demonstrating the presence of a heterogeneous population into the recellularized scaffolds. Periodic Acid Schiff-Diastase staining confirmed the presence of glycogen storage, indicating that differentiate cells acquired a hepatic-like phenotype. In conclusion, these preliminary results suggested that mouse placental scaffolds might be used as a biological platform for stem cells differentiation into hepatic-like cells and their establishment, which may be a promissing biomaterial for hepatic tissue reconstruction.
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Placenta , Alicerces Teciduais , Feminino , Gravidez , Animais , Camundongos , Projetos Piloto , Alicerces Teciduais/química , Fígado/metabolismo , Hepatócitos/metabolismo , Diferenciação Celular , Células-Tronco Embrionárias , Matriz Extracelular/metabolismoRESUMO
Cloning by somatic cell Nuclear Transfer (SCNT) is a powerful technology capable of reprograming terminally differentiated cells to totipotency for generating whole animals or pluripotent stem cells for use in cell therapy, drug screening, and other biotechnological applications. However, the broad usage of SCNT remains limited due to its high cost and low efficiency in obtaining live and healthy offspring. In this chapter, we first briefly discuss the epigenetic constraints responsible for the low efficiency of SCNT and current attempts to overcome them. We then describe our bovine SCNT protocol for delivering live cloned calves and addressing basic questions about nuclear reprogramming. Other research groups can benefit from our basic protocol and build up on it to improve SCNT in the future. Strategies to correct or mitigate epigenetic errors (e.g., correcting imprinting loci, overexpression of demethylases, chromatin-modifying drugs) can integrate the protocol described here.
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Técnicas de Transferência Nuclear , Células-Tronco Pluripotentes , Bovinos , Animais , Técnicas de Transferência Nuclear/veterinária , Clonagem de Organismos/métodos , Biotecnologia , Clonagem MolecularRESUMO
Besides their canonical roles as energy sources, short-chain fatty acids act as metabolic regulators of gene expression through histone posttranslational modifications. Ketone body ß-hydroxybutyrate (BHB) causes a novel epigenetic modification, histone lysine ß-hydroxybutyrylation (Kbhb), which is associated with genes upregulated in starvation-responsive metabolic pathways. Dairy cows increase BHB in early lactation, and the effects of this increase on cellular epigenomes are unknown. We searched for and identified that Kbhb is present in bovine tissues in vivo and confirmed that this epigenetic mark is responsive to BHB in bovine and human fibroblasts cultured in vitro in a dose-dependent manner. Maturation of cumulus-oocyte complexes with high concentrations of BHB did not affect the competence to complete meiotic maturation or to develop until the blastocyst stage. BHB treatment strongly induced H3K9bhb in cumulus cells, but faintly in oocytes. RNA-seq analysis in cumulus cells indicated that BHB treatment altered the expression of 345 genes. The downregulated genes were mainly involved in glycolysis and ribosome assembly pathways, while the upregulated genes were involved in mitochondrial metabolism and oocyte development. The genes and pathways altered by BHB will provide entry points to carry out functional experiments aiming to mitigate metabolic disorders and improve fertility in cattle.
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Ácido 3-Hidroxibutírico , Células do Cúmulo , Epigênese Genética , Histonas , Lisina , Oócitos , Ácido 3-Hidroxibutírico/metabolismo , Ácido 3-Hidroxibutírico/farmacologia , Animais , Bovinos , Células do Cúmulo/metabolismo , Feminino , Histonas/metabolismo , Humanos , Lisina/metabolismo , Oócitos/metabolismoRESUMO
Tissue engineering is gaining use to investigate the application of its techniques for infertility treatment. The use of pluripotent embryonic cells for in vitro production of viable spermatozoa in testicular scaffolds is a promising strategy that could solve male infertility. Due to cell-extracellular matrix (ECM) interactions, here we aim to investigate the differentiation of embryoid bodies (EBs) in cultured into decellularized rat testis scaffolds. Decellularized testis (P = 0.019) with a low concentration of gDNA (30.58 mg/ng tissue) was obtained by sodium dodecyl sulfate perfusion. The structural proteins (collagens type I and III) and the adhesive glycoproteins of ECM (laminin and fibronectin) were preserved according to histological and scanning electron microscopy (SEM) analyses. Then, decellularized rat testis were cultured for 7 days with EB, and EB mixed with retinoic acid (RA) in non-adherent plates. By SEM, we observe that embryonic stem cells adhered in the decellularized testis ECM. By immunofluorescence, we verified the positive expression of HSD17B3, GDNF, ACRV-1, and TRIM-36, indicating their differentiation using RA in vitro, reinforcing the possibility of EB in male germ cell differentiation. Finally, recellularized testis ECM may be a promising tool for future new approaches for testicular cell differentiation applied to assisted reproduction techniques and infertility treatment.Abbreviations: ACRV-1: Acrosomal vesicle protein 1; ATB: Penicillin-streptomycin; DAPI: 4,6-Diamidino-2-phenylindole; EB: Embryoid bodies; ECM: Extracellular matrix; ESCs: Pluripotent embryonic stem cells; GAGs: Glycosaminoglycans; gDNA: Genomic DNA; GDNF: Glial cell line-derived neurotrophic factor; H&E: Hematoxylin and eosin; HSD17B3: 17-beta-Hydroxysteroid dehydrogenase type 3; PBS: Phosphate-buffered saline; PGCLCs: Primordial germ-cell-like cells; RA: Retinoic acid; SDS: Sodium dodecyl sulfate; SEM: Scanning electron microscopy; SSCs: Spermatogonial stem cells; TRIM-36: Tripartite Motif Containing 36.
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Corpos Embrioides , Engenharia Tecidual , Animais , Diferenciação Celular , Matriz Extracelular , Masculino , Ratos , Testículo , Alicerces TeciduaisRESUMO
Orchestrated events, including extensive changes in epigenetic marks, allow a somatic nucleus to become totipotent after transfer into an oocyte, a process termed nuclear reprogramming. Recently, several strategies have been applied in order to improve reprogramming efficiency, mainly focused on removing repressive epigenetic marks such as histone methylation from the somatic nucleus. Herein we used the specific and non-toxic chemical probe UNC0638 to inhibit the catalytic activity of the histone methyltransferases EHMT1 and EHMT2. Either the donor cell (before reconstruction) or the early embryo was exposed to the probe to assess its effect on developmental rates and epigenetic marks. First, we showed that the treatment of bovine fibroblasts with UNC0638 did mitigate the levels of H3K9me2. Moreover, H3K9me2 levels were decreased in cloned embryos regardless of treating either donor cells or early embryos with UNC0638. Additional epigenetic marks such as H3K9me3, 5mC, and 5hmC were also affected by the UNC0638 treatment. Therefore, the use of UNC0638 did diminish the levels of H3K9me2 and H3K9me3 in SCNT-derived blastocysts, but this was unable to improve their preimplantation development. These results indicate that the specific reduction of H3K9me2 by inhibiting EHMT1/2 during nuclear reprogramming impacts the levels of H3K9me3, 5mC, and 5hmC in preimplantation bovine embryos.
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Reprogramação Celular/genética , Metilação de DNA/genética , Desenvolvimento Embrionário/genética , Histona Metiltransferases/genética , Animais , Blastocisto , Bovinos , Diferenciação Celular , Clonagem de Organismos/métodos , Transferência Embrionária/métodos , Epigênese Genética/genética , Regulação da Expressão Gênica no Desenvolvimento/genética , Antígenos de Histocompatibilidade/genética , Histona-Lisina N-Metiltransferase/genética , Técnicas de Transferência Nuclear , Oócitos/crescimento & desenvolvimento , Processamento de Proteína Pós-Traducional/genética , Quinazolinas/farmacologiaRESUMO
A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has not been fixed in the paper.
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The rapid decline in fertility that has been occurring to high-producing dairy cows in the past 50 years seems to be associated with metabolic disturbances such as ketosis, supporting the need for research to improve our understanding of the relations among the diet, metabolism and embryonic development. Recently, the ketone body ß-hydroxybutyrate (BOHB) was demonstrated to be a potent inhibitor of histone deacetylases (HDACs). Herein, we performed a series of experiments aiming to investigate the epigenetic effects of BOHB on histone acetylation in somatic cells, cumulus-oocyte complexes (COCs) and somatic cell nuclear transfer (SCNT) embryos. Treatment with BOHB does not increase histone acetylation in cells but stimulates genes associated with ketolysis and master regulators of metabolism. We further demonstrated that maturing COCs with high levels of BOHB does not affect their maturation rate or histone acetylation but increases the expression of PPARA in cumulus cells. Treatment of somatic cell nuclear transfer zygotes with BOHB causes hyperacetylation, which is maintained until the blastocyst stage, causing enhanced FOXO3A expression and blastocyst production. Our data shed light on the epigenetic mechanisms caused by BOHB in bovine cells and embryos and provide a better understanding of the connection between nutrition and reproduction.
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Ácido 3-Hidroxibutírico/farmacologia , Embrião de Mamíferos/citologia , Desenvolvimento Embrionário/efeitos dos fármacos , Fertilidade/fisiologia , Inibidores de Histona Desacetilases/farmacologia , Oócitos/metabolismo , Ácido 3-Hidroxibutírico/biossíntese , Ácido 3-Hidroxibutírico/genética , Acetilação , Animais , Blastocisto/citologia , Bovinos , Linhagem Celular , Células do Cúmulo/metabolismo , Feminino , Proteína Forkhead Box O3/biossíntese , Regulação da Expressão Gênica no Desenvolvimento , Células HEK293 , Inibidores de Histona Desacetilases/metabolismo , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Técnicas de Transferência Nuclear , Estresse Oxidativo/efeitos dos fármacos , PPAR alfa/biossíntese , GravidezRESUMO
Hybrids between species are often infertile and extremely rare among mammals. Mules, i.e. crossing between the horse and the donkey, on the other hand are very common in agricultural and leisure practices due to their enhanced post-natal physical characteristics that is believed to occur for outbreeding or hybrid vigor. Since no reports are availableon the effects of hybrid vigor during early development, this study focused on characterizing the intrauterine development of mule conceptuses during critical embryo-to-fetus transition period. Nine embryos and fetuses of early gestation, obtained after artificial insemination and transcervical flushing, were evaluated by means of gross anatomy and histology and compared to data available for the equine. We found that some events, such as C-shape turning, apearence of branchial archs, limb and tail buds, formation of primary and secondary brain vesicles, heart compartmentalization, and development of somites, occurred slightly earlier in the mule. Nonetheless, no major differences were observed in other developmental features, suggesting similarities between the mule and the horse development. In conclusion, these data suggest that the effect of hybrid vigor is present during intrauterine development in the mule, at least with regard to its maternal parent.
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Hybrids between species are often infertile and extremely rare among mammals. Mules, i.e. crossing between the horse and the donkey, on the other hand are very common in agricultural and leisure practices due to their enhanced post-natal physical characteristics that is believed to occur for outbreeding or hybrid vigor. Since no reports are availableon the effects of hybrid vigor during early development, this study focused on characterizing the intrauterine development of mule conceptuses during critical embryo-to-fetus transition period. Nine embryos and fetuses of early gestation, obtained after artificial insemination and transcervical flushing, were evaluated by means of gross anatomy and histology and compared to data available for the equine. We found that some events, such as C-shape turning, apearence of branchial archs, limb and tail buds, formation of primary and secondary brain vesicles, heart compartmentalization, and development of somites, occurred slightly earlier in the mule. Nonetheless, no major differences were observed in other developmental features, suggesting similarities between the mule and the horse development. In conclusion, these data suggest that the effect of hybrid vigor is present during intrauterine development in the mule, at least with regard to its maternal parent.(AU)
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Animais , Equidae/anatomia & histologia , Equidae/crescimento & desenvolvimentoRESUMO
Hybrids between species are often infertile and extremely rare among mammals. Mules, i.e. crossing between the horse and the donkey, on the other hand are very common in agricultural and leisure practices due to their enhanced post-natal physical characteristics that is believed to occur for outbreeding or hybrid vigor. Since no reports are availableon the effects of hybrid vigor during early development, this study focused on characterizing the intrauterine development of mule conceptuses during critical embryo-to-fetus transition period. Nine embryos and fetuses of early gestation, obtained after artificial insemination and transcervical flushing, were evaluated by means of gross anatomy and histology and compared to data available for the equine. We found that some events, such as C-shape turning, apearence of branchial archs, limb and tail buds, formation of primary and secondary brain vesicles, heart compartmentalization, and development of somites, occurred slightly earlier in the mule. Nonetheless, no major differences were observed in other developmental features, suggesting similarities between the mule and the horse development. In conclusion, these data suggest that the effect of hybrid vigor is present during intrauterine development in the mule, at least with regard to its maternal parent.
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Animais , Equidae/anatomia & histologia , Equidae/crescimento & desenvolvimentoRESUMO
Oocytes from dairy cattle and buffaloes have severely compromised developmental competence during summer. While analysis of gene expression is a powerful technique for understanding the factors affecting developmental hindrance in oocytes, analysis by real-time reverse transcription PCR (RT-PCR) relies on the correct normalization by reference genes showing stable expression. Furthermore, several studies have found that genes commonly used as reference standards do not behave as expected depending on cell type and experimental design. Hence, it is recommended to evaluate expression stability of candidate reference genes for a specific experimental condition before employing them as internal controls. In acknowledgment of the importance of seasonal effects on oocyte gene expression, the aim of this study was to evaluate the stability of expression levels of ten well-known reference genes (ACTB, GAPDH, GUSB, HIST1H2AG, HPRT1, PPIA, RPL15, SDHA, TBP and YWHAZ) using oocytes collected from different categories of dairy cattle and buffaloes during winter and summer. A normalization factor was provided for cattle (RPL15, PPIA and GUSB) and buffaloes (YWHAZ, GUSB and GAPDH) based on the expression of the three most stable reference genes in each species. Normalization of non-reference target genes by these reference genes was shown to be considerably different from normalization by less stable reference genes, further highlighting the need for careful selection of internal controls. Therefore, due to the high variability of reference genes among experimental groups, we conclude that data normalized by internal controls can be misleading and should be compared to not normalized data or to data normalized by an external control in order to better interpret the biological relevance of gene expression analysis.
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Expressão Gênica , Genes Essenciais , Oócitos/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/normas , Reação em Cadeia da Polimerase Via Transcriptase Reversa/normas , Animais , Búfalos , Bovinos , Indústria de Laticínios , Feminino , Perfilação da Expressão Gênica , Oócitos/citologia , Padrões de Referência , Estações do AnoRESUMO
The mRNAs accumulated in oocytes provide support for embryo development until embryo genomic activation. We hypothesized that the maternal mRNA stock present in bovine oocytes is associated with embryo development until the blastocyst stage. To test our hypothesis, we analyzed the transcriptome of the oocyte and correlated the results with the embryo development. Our goal was to identify genes expressed in the oocyte that correlate with its ability to develop to the blastocyst stage. A fraction of oocyte cytoplasm was biopsied using micro-aspiration and stored for further expression analysis. Oocytes were activated chemically, cultured individually and classified according to their capacity to develop in vitro to the blastocyst stage. Microarray analysis was performed on mRNA extracted from the oocyte cytoplasm fractions and correlated with its ability to develop to the blastocyst stage (good quality oocyte) or arrest at the 8-16-cell stage (bad quality oocyte). The expression of 4320 annotated genes was detected in the fractions of cytoplasm that had been collected from oocytes matured in vitro. Gene ontology classification revealed that enriched gene expression of genes was associated with certain biological processes: 'RNA processing', 'translation' and 'mRNA metabolic process'. Genes that are important to the molecular functions of 'RNA binding' and 'translation factor activity, RNA binding' were also enriched in oocytes. We identified 29 genes with differential expression between the two groups of oocytes compared (good versus bad quality). The content of mRNAs expressed in metaphase II oocytes influences the activation of the embryonic genome and enables further develop to the blastocyst stage.
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Blastocisto/citologia , Embrião de Mamíferos/citologia , Desenvolvimento Embrionário , Regulação da Expressão Gênica no Desenvolvimento , Metáfase/genética , Oócitos/citologia , RNA Mensageiro/genética , Animais , Blastocisto/metabolismo , Bovinos , Células Cultivadas , Embrião de Mamíferos/metabolismo , Feminino , Perfilação da Expressão Gênica , Técnicas In Vitro , Análise de Sequência com Séries de Oligonucleotídeos , Oócitos/metabolismo , RNA Mensageiro Estocado/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Although somatic cell nuclear transfer (SCNT) is a promising tool, its potential use is hampered by the high mortality rates during the development to term of cloned offspring. Abnormal epigenetic reprogramming of donor nuclei after SCNT is thought to be the main cause of this low efficiency. We hypothesized that chromatin-modifying agents (CMAs) targeting chromatin acetylation and DNA methylation could alter the chromatin configuration and turn them more amenable to reprogramming. Thus, bovine fibroblasts were treated with 5-aza-2'-deoxycytidine (AZA) plus trichostatin (TSA) or hydralazine (HH) plus valproic acid (VPA) whereas, in another trial, cloned bovine zygotes were treated with TSA. The treatment of fibroblasts with either AZA+TSA or HH+VPA increased histone acetylation, but did not affect the level of DNA methylation. However, treatment with HH+VPA decreased cellular viability and proliferation. The use of these cells as nuclear donors showed no positive effect on pre- and postimplantation development. Regarding the treatment of cloned zygotes with TSA, treated one-cell embryos showed an increase in the acetylation patterns, but not in the level of DNA methylation. Moreover, this treatment revealed no positive effect on pre- and postimplantation development. This work provides evidence the treatment of either nuclear donor cells or cloned zygotes with CMAs has no positive effect on pre- and postimplantation development of cloned cattle.
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Bovinos , Núcleo Celular/efeitos dos fármacos , Montagem e Desmontagem da Cromatina/efeitos dos fármacos , Clonagem de Organismos/métodos , Desenvolvimento Embrionário/efeitos dos fármacos , Inibidores de Histona Desacetilases/farmacologia , Zigoto/efeitos dos fármacos , Acetilação/efeitos dos fármacos , Animais , Azacitidina/análogos & derivados , Azacitidina/farmacologia , Bovinos/embriologia , Bovinos/genética , Bovinos/metabolismo , Núcleo Celular/fisiologia , Células Cultivadas , Decitabina , Feminino , Histonas/metabolismo , Hidralazina/farmacologia , Ácidos Hidroxâmicos/farmacologia , Técnicas de Transferência Nuclear/veterinária , Gravidez , Nascimento a Termo/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacos , Ácido Valproico/farmacologia , Zigoto/fisiologiaRESUMO
Ooplasm transfer has been used successfully to treat infertility in women with ooplasmic insufficiency and has culminated in the birth of healthy babies. To investigate whether mitochondrial dysfunction is a factor in ooplasmic insufficiency, bovine oocytes were exposed to ethidium bromide, an inhibitor of mitochondrial DNA replication and transcription, during in-vitro maturation (IVM). Exposure of immature oocytes to ethidium bromide for 24h during IVM hampered meiotic resumption and the migration of cortical granules. However, a briefer treatment with ethidium bromide during the last 4h of IVM led to partial arrest of preimplantation development without affecting oocyte maturation. Ooplasm transfer was then performed to rescue the oocytes with impaired development. In spite of this developmental hindrance, transfer of normal ooplasm into ethidium bromide-treated oocytes resulted in a complete rescue of embryonic development and the birth of heteroplasmic calves. Although this study unable to determine whether developmental rescue occurred exclusively through introduction of unaffected mitochondria into ethidium bromide-damaged oocytes, e.g. ethidium bromide may also affect other ooplasm components, these results clearly demonstrate that ooplasm transfer can completely rescue developmentally compromised oocytes, supporting the potential use of ooplasm transfer in therapeutic applications.
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Citoplasma/transplante , Etídio/farmacologia , Oócitos/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Animais , Bovinos , Citoplasma/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Feminino , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/fisiologia , Oócitos/citologia , Oócitos/metabolismoRESUMO
Background: The ability to create tissues using pluripotent stem cells to repair or replace tissue lost due to damage, i.e. regenerative medicine, is developing very rapidly in many fields of human medicine. For veterinarians, regenerative medicine has focused mainly in the use of stem cells for arthritis and tendon ligament repair, indicating a need for treating musculoskeletal injuries. Our objective is to review the available approaches being used to derive pluripotent stem cells and discuss their potential use for regenerative medicine in the horse. Review: Adult adipose- and bone marrow-derived mesenchymal stem cells (MSC) are being used in practice to treat injuries in horses. However, there is scarce scientific evidence of their effectiveness and little is known of the mechanisms by which such cell preparations improve the healing process. For instance, although early healing response of articular cartilage injury was improved by treatment with injection of MSC, they did not enhance the long-term tissue response, indicating that cell proliferation was attenuated. Better protocols for the isolation and clinical testing of equine MSC are required to confirm healing properties. In contrast to MSC, embryonic stem cells (ESC) derived from the inner-cell- mass (ICM) of blastocyst stage embryos carry the ability to proliferate indefinitely in vitro and, given appropriate and favorable conditions, can differentiate into any tissue in the body. Parthenogenesis (PG) and somatic cell nuclear transfer (SCNT) are used to obtain a genetic match to the host animal and, thereby, eliminate the risk of inducing immune rejection of the grafted tissue. However, apart from the typical markers of pluripotency, equine ESC also express markers of trophoblastic tissues, indicating that they are different and possibly less able to differentiate than the ESC lines obtained in other species. Consequently, further studies are underway to identify conditions to obtain fully pluripotent ESC lines from equine SCNT embryos. To overcome the limitations of ESC lines derived from equine embryos, induced pluripotent stem cells (iPSC) were derived using a piggyBac transposon-based method to deliver transgenes containing the reprogramming factors Oct4, Sox2, Klf4 and c-Myc, expressed in a temporally controlled fashion. Our established fetal-derived iPSC lines express hallmark pluripotency markers, display a stable karyotype after prolonged culture, and are able to form teratomas in immunodeficient mice containing tissues from all three embryonic layers. By establishing a protocol for deriving stable iPSC lines in the horse, we expect that new opportunities will be shortly developed for regenerative therapies in this species. Conclusion: It is possible to derive autologous pluripotent stem cells in horses by using both ESC and iPSC-derived approaches. Although ESC lines are generally the gold standard of pluripotency, further research is required to improve the proliferative and pluripotency characteristics for clinical applications. On the other hand, equine iPSC show excellent stability during prolonged in vitro culture and have the capacity to differentiate into the three germ layers in vivo, suggesting that they could soon be used in pre-clinical trials. Therefore, further studies need to be performed to establish reliable protocols for assessing the regenerative properties of iPS and ESC for equine muscle-skeletal injuries.
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Animais , Artrite/veterinária , Ligamento Patelar/transplante , Células-Tronco Pluripotentes/fisiologia , Células-Tronco Embrionárias , Cavalos/lesões , Medicina Regenerativa/tendênciasRESUMO
Nuclear-mitochondrial incompatibilities may be responsible for the development failure reported in embryos and fetuses produced by interspecies somatic cell nuclear transfer (iSCNT). Herein we performed xenooplasmic transfer (XOT) by introducing 10 to 15% of buffalo ooplasm into bovine zygotes to assess its effect on the persistence of buffalo mitochondrial DNA (mtDNA). Blastocyst rates were not compromised by XOT in comparison to both in vitro fertilized embryos and embryos produced by transfer of bovine ooplasm into bovine zygotes. Moreover, offspring were born after transfer of XOT embryos to recipient cows. Buffalo mtDNA introduced in zygotes was still present at the blastocyst stage (8.3 vs. 9.3%, p = 0.11), indicating unaltered heteroplasmy during early development. Nonetheless, no vestige of buffalo mtDNA was found in offspring, indicating a drift to homoplasmy during later stages of development. In conclusion, we show that the buffalo mtDNA introduced by XOT into a bovine zygote do not compromise embryo development. On the other hand, buffalo mtDNA was not inherited by offspring indicating a possible failure in the process of interspecies mtDNA replication.
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Búfalos , Técnicas de Transferência Nuclear , Animais , Sequência de Bases , Bovinos , Primers do DNA , DNA Mitocondrial/genética , ZigotoRESUMO
Ooplasmic transfer (OT) has been used in basic mouse research for studying the segregation of mtDNA, as well as in human assisted reproduction for improving embryo development in cases of persistent developmental failure. Using cattle as a large-animal model, we demonstrate that the moderate amount of mitochondria introduced by OT is transmitted to the offspring's oocytes; e.g., modifies the germ line. The donor mtDNA was detectable in 25% and 65% of oocytes collected from two females. Its high variation in heteroplasmic oocytes, ranging from 1.1% to 33.5% and from 0.4% to 15.5%, can be explained by random genetic drift in the female germ line. Centrifugation-mediated enrichment of mitochondria in the pole zone of the recipient zygote's ooplasm and its substitution by donor ooplasm led to elevated proportions of donor mtDNA in reconstructed zygotes compared with zygotes produced by standard OT (23.6% +/- 9.6% versus 12.1% +/- 4.5%; P < 0.0001). We also characterized the proliferation of mitochondria from the OT parents-the recipient zygote (Bos primigenius taurus type) and the donor ooplasm (B. primigenius indicus type). Regression analysis performed for 57 tissue samples collected from the seven OT fetuses at different points during fetal development found a decreasing proportion of donor mtDNA (r(2) = 0.78). This indicates a preferred proliferation of recipient taurine mitochondria in the context of the nuclear genotype of the OT recipient expressing a B. primigenius indicus phenotype.
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Citoplasma/transplante , Mitocôndrias/fisiologia , Técnicas de Transferência Nuclear , Oócitos/citologia , Animais , Bovinos , Células Cultivadas , Corrente Citoplasmática/fisiologia , DNA Mitocondrial/genética , Técnicas de Cultura Embrionária , Transferência Embrionária/veterinária , Embrião de Mamíferos/metabolismo , Embrião de Mamíferos/fisiologia , Feminino , Desenvolvimento Fetal/fisiologia , Células Germinativas/citologia , Células Germinativas/ultraestrutura , Técnicas de Transferência Nuclear/veterinária , Oócitos/ultraestrutura , Gravidez , Doadores de TecidosRESUMO
Background : A broader view of living systems complexity is bringing important contributions to biological sciences, since the genome expression is affected by other classes of molecules, which in their turn interact themselves in cellular metabolic pathways and biochemical networks. This level of information has been made possible by the emergence of the omic strategies, such as proteomics, metabolomics and lipidomics, that are mainly based on mass spectrometry (MS) platforms. MS has presented an incredible development over the last years, evolving to a powerful and universal analytical technique. Its ability to analyze proteins and small molecules such as lipids, sugars and metabolites at the structural level, with sensitivity and speed inconceivable a few years ago, is the major driving force in the omic fields. The development of electrospray and matrix-assisted laser desorption/ionization (MALDI) ionization techniques has decisively contributed to the many applications of this technology nowadays. Herein, we present and discuss omic concepts and strategies, as well as detail basic principles of MS. Applications and future perspectives of these approaches are focused in the reproductive medicine area. Review: The omic technologies propose global characterization of specific classes of target biomolecules of cellular systems as a strategy to achieve comprehensive understanding of biological functions. The genomics, aimed at performing the entire genetic sequencing of organisms, represented the seminal step towards the understanding of the complex logic that orchestrates the function of all organisms or the defects leading to diseases. But to express the phenotype, information needs to flow from DNA via carrier biomolecules through processes that are being addressed by new omic sciences such as the transcriptomics, proteomics, metabolomics, glycomics, lipidomics, and fluxomics. Mass spectrometry (MS) is nowadays the most powerful technique for the structural characterization of biomolecules, and has therefore become the central technique for the omic sciences. Using revolutionary ionization techniques such as electrospray (ESI) and matrix-assisted laser desorption ionization (MALDI), a wide range of biomolecules such as peptides, proteins, lipids and sugars are efficiently transferred in intact ionized forms to the gas phase for MS analysis. The development of ESI-MS and MALDI-MS has been awarded the Nobel Prize for Chemistry in 2002, rocketing the application of MS in the omic sciences. More recently, ambient ionization MS techniques, such as desorption electrospray ionization (DESI) and easy ambient sonic-spray ionization (EASI), have been developed for ionization in the open atmosphere, in a workup free and high throughput fashion directly from sample in their original environments. For the more complex samples, the coupling with separation techniques such as liquid chromatrography (LC) as well as the use of tandem MS (LC-MS/MS) has allowed comprehensive mixture characterization of major biomolecules. Conclusion: This manuscript describes recent advances of MS in the proteomics, metabolomics and lipidomics for biological sciences, and points out the relevant contributions that MS is likely to bring to fundamental and applied research in human and animal embryo biotechnologies.
Assuntos
Humanos , Animais , Espectrometria de Massas , Proteômica/tendências , Embrião de Mamíferos , Metabolômica/tendências , Lipidômica/tendênciasRESUMO
The mechanisms controlling the outcome of donor cell-derived mitochondrial DNA (mtDNA) in cloned animals remain largely unknown. This research was designed to investigate the kinetics of somatic and embryonic mtDNA in reconstructed bovine embryos during preimplantation development, as well as in cloned animals. The experiment involved two different procedures of embryo reconstruction and their evaluation at five distinct phases of embryo development to measure the proportion of donor cell mtDNA (Bos indicus), as well as the segregation of this mtDNA during cleavage. The ratio of donor cell (B. indicus) to host oocyte (B. taurus) mtDNA (heteroplasmy) from blastomere(NT-B) and fibroblast(NT-F) reconstructed embryos was estimated using an allele-specific PCR with fluorochrome-stained specific primers in each sampled blastomere, in whole blastocysts, and in the tissues of a fibroblast-derived newborn clone. NT-B zygotes and blastocysts show similar levels of heteroplasmy (11.0% and 14.0%, respectively), despite a significant decrease at the 9-16 cell stage (5.8%; p<0.05). Heteroplasmy levels in NT-F reconstructed zygotes, however, increased from an initial low level (4.7%), to 12.9% (p<0.05) at the 9-16 cell stage. The NT-F blastocysts contained low levels of heteroplasmy (2.2%) and no somatic-derived mtDNA was detected in the gametes or the tissues of the newborn calf cloned. These results suggest that, in contrast to the mtDNA of blastomeres, that of somatic cells either undergoes replication or escapes degradation during cleavage, although it is degraded later after the blastocyst stage or lost during somatic development, as revealed by the lack of donor cell mtDNA at birth.